地形斜坡对东海黑潮陆架坡折锋稳定性影响研究

为了研究地形斜坡对东海黑潮陆架坡折锋稳定性的影响,利用简化的线性原始方程,在一定背景流的情况下,主要从增长率、相速度、空间结构和能量方面分析海底地形斜坡变化对坡折锋稳定性的影响。模式结果表明,平底地形时,扰动的强度大且扰动区域广,但有地形斜坡时,扰动区域变窄,强度变弱,地形对坡折锋起稳定性作用。通过能量分析得出东海黑潮陆架坡折锋是正压和斜压的混合不稳定,其中斜压不稳定占主导地位。实验分析得出,地形对东海黑潮陆架坡折锋起稳定作用,斜坡增大,斜压不稳定和正压不稳定均减弱,斜压不稳定减弱更明显。

Topographic slope influences on the stability of shelf break fronts in the Kuroshio of the East China Sea

This study investigated the stability of shelf break fronts using the primitive equations applied to a continuously stratified flow in a geostrophic balance, with a focus on the effects of the shelf slope on the stability of the shelf break front and on the characteristics of the most unstable modes. The results of this linear study indicated that the presence of a bottom slope stabilized the background current. Growth rates, phase speeds, and spatial structures of the most unstable perturbation strongly depend on the topographic parameters. The findings of this study implied that the shelf break front has a mixed instability. As the slope increases, both the baroclinic instability and the barotropic instability decrease, and the baroclinic instability becomes weaker.